1. Field of the Invention
The present invention relates to a speed change device for a transmission under no speed change or under acceleration or deceleration of the torque of a driving shaft connecting an electric or pneumatic driving unit to a driven shaft (hereinafter referred to as "working shaft").
2. Prior Art
For enabling mechanical transmission of torque from a driving shaft to a working shaft it was hitherto necessary to provide several speed change devices of either a gear type each thereof having a fixed speed change ratio or a bail planetary type so that the one best suited for the particular work can be chosen. For the user, it was not only troublesome but also meant an increased financial burden. Another problem was that it occupied a large portion of the limited clinical space.